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New findings from Japan and the United Kingdom in the area of imaging described Imaging
Investigators in Japan and the United Kingdom have published new imaging data.
Study 1: Transthoracic Doppler echocardiography (TTDE) can assess the coronary arterial tone by measuring the responses of coronary flow velocity (CFV) and coronary flow velocity reserve (CFVR) to nitroglycerin (NTG) administration.
According to recent research from Japan, "As coronary flow velocity (CFV) is inversely related to the luminal size that exists for the myocardial bed, the elevated arterial tone can be assessed as the higher flow velocity in the epicardial artery. We examined the usefulness of (TTDE) for the assessment of coronary arterial tone."
"A total of 32 patients underwent TTDE and angiography," noted A. Takagi and colleagues at Tokyo Women's Medical Unive rsity. "The luminal diameter (LD) in the left anterior descending artery (LAD) was measured by using quantitative coronary angiography before and after nitroglycerin (NTG) administration. The ratio of post NTG LD to the control (LDNTG/Pre) was assessed as a standard parameter of coronary arterial tone."
"We also measured CFV and CFV reserve (CFVR) at the LAD by TTDE," the investigators continued. "We evaluated the change of CFV (CFVNTG/Pre) and CFVR (CFVRNTG/Pre) following NTG administration. The LD increased from 1.98±0.46 to 2.51±0.34 mm (p<0.001), while the CFV decreased from 23.9±10.0 to 16.3±5.6 cm/s (p<0.03), and the CFVR increased from 2.39±0.65 to 3.56±1.12 (p<0.001). There were significant correlations between CFVNTG/Pre and LDNTG/Pre (p<0.0001, R2=0.532), and between the CFVRNTG/Pre and LDNTG/Pre (p<0.0001, R2=0.715)."
The researchers concluded, "TTDE can assess the coronary arterial tone by measuring the responses of CFV and CFVR to NTG administration."
Takagi and colleagues published their study in the Circulation Journal (Non-invasive assessment of coronary arterial tone using trans-thoracic Doppler echocardiography.
For additional information, contact A. Takagi, Tokyo Women's Medical University, Dept. of Cardiology, 8-1 Kawada Cho, Tokyo 1628666, Japan.
Study 2: Noninvasive measurement of coronary flow velocity reserve by transthoracic Doppler echocardiography accurately reflects the physiological severity of coronary narrowing due to restenosis after percutaneous coronary intervention (PCI).
According to a recent report from Japan, "Noninvasive methods that have the ability to accurately detect restenosis have been desired in the selection of patients requiring further angiographic evaluation. The present study sought to evaluate the diagnostic potential of transthoracic Doppler echocardiography (TTDE), a noninvasive method for evaluating coronary flow velocity reserve (CFVR), in detecting restenosis after percutaneous coronary intervention (PCI)."
K. Hirata and colleagues at Osaka City University School of Medicine explained, "We studied 107 consecutive patients 6 months after undergoing successful PCI on the left anterior descending coronary artery (LAD) lesion for relief of angina pectoris. The flow velocity in the distal LAD was measured by TTDE both at rest and during intravenous infusion of adenosine triphosphate. CFVR was calculated as the ratio of hyperemic to basal mean diastolic flow velocities."
They continued, "We defined a reversible perfusion defect in exercise Tl-201 single-photon emission computed tomography (SPECT) as restenosis. The CFVR measurements by TME were compared with the results of SPECT. Complete TTDE data were acquired for 105 of the 107 study patients. A contrast agent was used to obtain adequate Doppler signals in 29 patients."
"Of the 105 patients, there were 18 patients with abnormal perfusion (group A) and 87 patients with normal perfusion (group B) in the LAD territories on Tl-201 SPECT," reported the investigators. "CFVR was greater in group B than in group A (1.7±0.5 vs. 3.7±0.8, p<0.0001, respectively). There were 17 patients with CFVR<2 and 88 patients with CFVRgreater than or equal to2. CFVR<2 predicted restenosis determined by Tl-201 SPECT, with a sensitivity of 94% and a specificity of 100%."
"Noninvasive measurement of CFVR by TTDE accurately reflects the physiological severity of coronary narrowing due to restenosis after PCI," concluded the researchers. "This method has the possibility of reducing the number of unnecessary coronary angiographies after PCI."
Hirata and colleagues published their study in the Journal of the American Society of Echocardiography (Noninvasive diagnosis of restenosis by transthoracic Doppler echocardiography after percutaneous coronary intervention: Comparison with exercise Tl-SPECT.
For additional information, contact H. Watanabe, Osaka City University, School of Medicine, Dept. Internal Medicine & Cardiology, Abeno Ku, 1-4-3 Asahimachi, Osaka 5458585, Japan.
Study 3: Transthoracic 2-D echocardiography used as an image guide for coronary sinus cannulation is feasible and as rapid as standard x-ray fluoroscopy.
Scientists in People's Republic of China conducted a study "to assess the value of transthoracic echocardiography (TTE) as an image guide in placing a coronary sinus catheter into the coronary sinus."
J.Q. Zhong and colleagues at Shandong University in Ji Nan wrote, "Sixty consecutive patients undergoing electrophysiologic study were randomized to TTE (30 patients, 'TTE group') or x-ray fluoroscopy (30 patients, 'x-ray group') as an image guide to assist in the placement of a coronary sinus catheter."
"The success rate of placing the coronary sinus catheter was 96.7% in the TTE group and 100% in the x-ray group (p>0.05). The procedure duration was 5.8±5.7 minutes in the TTE group and 5.9±3.3 minutes in x-ray group (p>0.05). The x-ray exposure time was 0.15±0 minutes in the TTE group and 4.2±2.8 minutes in the x-ray group (p<0.0001)," the authors reported.
"Using TTE as an image guide, coronary sinus cannulation is feasible and as rapid as standard x-ray fluoroscopy, without the radiation risk," they concluded."